<nav class="navbar navbar-light bg-light">
  <a class="navbar-brand" href="/">君不见 MyBlog</a>
  <form class="form-inline" action="search" method="post">
    <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search" name="Search">
    <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
  </form>
</nav>